c - Symbol table and semantic analysis for compiler -

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i'm working on building compiler (without using tools -like lex or bison) c language (a simpler one) , have gotten past lexer , parser. not sure way doing parser correct or not. because, far parsing, ie check if syntax correct or not , haven't used linked lists @ all. basically, parser looks this: suppose syntax - 

<program> ::= <program_header> <program_body> <program_header>::= program <identifier> <program_body> ::= (<declaration>;)* begin (<statement>;)* end program

my program looks this:

parser() { char *next_token; next_token = get_token(); check_for_program(next_token); } check_for_program(next_token) { check_for_program_header(next_token); if (header_found) check_for_program_body(); }...

i have functions non-terminals , call them @ appropriate times , checking keywords "strcmp". method ok?

from point, how go doing semantic analysis? should start building symbol table?

any suggestion or pointer think great! thank much

well common , rather simple way of doing create recursive descent parser i.e. create functions correspond syntax (which sort of seem have started already):

e.g.

<program> ::= <program_header> <program_body> <program_header>::= program <identifier> <program_body> ::= (<declaration>;)*

would correspond like

void program() {   program_header();   program_body(); }  void program_header()  {    char* program_token = get_token();    char* identifier = get_token();    if (identifier==null) report_error();    ... }  void program_body() {    declaration();    ... }

and inside each function put semantic checks. need symbol table, either global construct if don't want handle scopes or have kind of stack of symbol tables.


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